Age. Exactly how long does a gecko live?

I seem to find a lot of conflicting information on exactly how long a leopard gecko is supposed to live.
Some say 10 years.. some say 20.. some say over 20... and everything in between.

My gecko is almost 9 now and the vet seems to think she is "old".
Is she?

Any long time owner/breeder know an average lifespan of a healthy gecko?

I just adopted one that is about 15 years old. His first owner had him since 1997!

He is still pretty chunky (79g), eats well, and has a little attitude too LOL.

geckos can live into their 20's if they have the proper care and husbandry ect.

not sure it is valid, but i heard from a reputable breeder, that one guy has one that is 31 years old....a leopard.

From what I've read average is between 10-15 years. Those that have their geckos go above 20+ years are actually more rare. It's like your cats & dogs, they can live that long, but most of them don't.

It depends on many things.

Was the gecko healthy to begin with?
Breeding, high fat diet, poor husbandry and stress will lead to a shortened lifespan.
My cousin's gecko is 13 years old and is still active. She never allows her to go over 80 grams.
She only feeds her crickets and silkworms. The other people I know that have had their geckos live over 15 are very cautious of weight and insects they feed. They have NEVER fed waxworms or pinkies. Their diets mostly consist of crickets, silkworms, roaches and hornworms. They make sure their whole body remains warm, not just their stomache.

mealworms= do not gutload well, do not hold dust well, can be difficult to digest.
superworms= do not gutload well, do not hold dust well, higher in fat content than mealworms.

Of course a breeder has too many and cannot afford to have them all live in optimal conditions.
Besides their goal is to sell them and not keep them forever.